xtabond2 dgdp gdpcap invlow edu dpop period*, gmm(l.invlow edu gdp) iv(dpop period*) robust noconstant

xtabond2 dgdp gdpcap invlow edu dpop ifi period*, gmm(l.invlow l.ifi edu gdp) iv(dpop period*) robust noconstant

xtabond2 dgdp gdpcap invhigh edu dpop period*, gmm(l.invhigh edu gdp) iv(dpop period*) robust noconstant

xtabond2 dgdp gdpcap invhigh edu dpop ifi period*, gmm(l.invhigh l.ifi edu gdp) iv(dpop period*) robust noconstant

